Seismic Hazard Analysis, although aiming to provide a fair estimate of the ground acceleration at a given site, sometimes underestimates the actual recorded values in certain regions. For example, the earthquake of August 8, 2010 (30 July 2010) in the city of Torbat Heydarieh, with a moment magnitude of 5.9, recorded a peak ground acceleration (PGA) of 425 cm/s² at a local station a value significantly higher than the predictions from global, regional, or even local attenuation models and seismic codes for that area. This considerable discrepancy highlights the significant role of local mechanisms in amplifying ground motion. The objective of this study is to investigate various factors contributing to this high acceleration, including site soil amplification, rupture directivity, and basin response effects. To this end, the study employed component analysis of accelerograms, continuous wavelet transform, pulse indicator methods, angular analysis of acceleration components, and spatial distribution of recorded acceleration. Additionally, the effect of directivity was modeled for two rupture initiation scenarios. Findings revealed that site soil amplification alone could not explain the observed high acceleration. The analysis of rupture directivity indicated that the dominant acceleration component at near-fault stations like Torbat Heydarieh, Jangal, and Shadmehr was mainly perpendicular to the fault strike, with noticeable energy concentration in the early part of the record. Although Baker’s pulse indicator classified the earthquake as non-pulse-like, the pulse-to-total energy ratio (0.446) according to the Zhai criterion indicated a possible occurrence of directional pulse. However, with a more precise modeling of directivity using the Bils model (2024) and accounting for potential errors in source motion, it was observed that directivity alone could not definitively explain the high ground acceleration. Ultimately, the investigation of basin effects showed that sedimentary basin amplification could justify the strong motion observed in the city center of Torbat Heydarieh. The geological analysis of the Torbat Heydariyeh region, along with comparison to the ground acceleration distribution map, indicates that peak ground accelerations are primarily located in areas with soft, alluvial, and low-strength soils. This spatial correlation confirms the effect of local site amplification, emphasizing the necessity of incorporating it into seismic hazard assessments and structural design. More complex phenomena—such as basin edge effects and overall basin effects—especially in areas with heterogeneous geological arrangements, can significantly influence ground motion, either amplifying or attenuating it. Overall, it can be concluded that the Torbat Heydariyeh earthquake was simultaneously influenced by three key factors: Rupture directivity, Site amplification and Amplification caused by sedimentary basin effects. The overlap of these phenomena, particularly in areas close to the fault, underscores the critical importance of accounting for local site effects in seismic hazard evaluations and earthquake-resistant design. Hence, to perform a precise analysis of site effects, it is essential to simultaneously and integrally examine various factors such as rupture directivity, dynamic soil properties, and the geometry and seismic response of the sedimentary basin.